58 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 64. 



1914, October 13 : 1, in spiral valve, still in cyst ; sand eels in stom- 

 ach. Cysts of this cestode are not uncommon in the flesh of the 

 sand eel, 



1922, August 29: 2, from 1 of 3 young spiny dogfish. Collected 

 by Dr. G. A. MacCallum. 



^ 1923, July 23 : 1. 

 August 4 : about 12 in each of 3 dogfish. 

 Vulpecula marina. 



1923, August 27 : 5 in spiral valve. 

 Larval stage. 



The cysts and plerocerci of this species are often club-shaped, or 

 gourd-shaped, the larger end being subglobular, the remainder, 

 which is of much smaller diameter and cylindrical, may be either 

 straight or curved. Usually encysted on viscera, and in intestinal 

 wall, but common in the flesh of sand eels, silverside, and young 

 herring. 



Acanthocottus octodecimspinosus. 



1904, October 28 : 1 cyst. 



1910, October 14 : A few cysts, some with degenerate tissue ; 8 fish 

 examined. 



Ammodytes mnericnnus. 



Collected in 4 of the years from 1905 to 1914, inclusive : On 1 date 

 in July, 2 cysts found by Dr. C. W. Hahn in the flesh near the tail 

 fin. On the same date 25 fish were examined and 1 cyst found on the 

 viscera; 4 dates in August — (1) 1 thin- walled cyst on visera; (2) 

 numerous characteristic plerocerci in thin-walled cysts on mesentary, 

 19 fish from stomach of squeteague ; on same date in a lot of 16 sand- 

 eels from the stomach of a bonito 2 cysts were found; (3) numerous, 

 encysted in muscles of most of about 40 sand-eels from the stomach 

 of a bonito; (4) many, in muscles, most abundant near caudal fin, 

 2 fish; 1 date in October, cysts, presumably from viscera, 12 fish; 1 

 date in November, a few cysts clustered in flesh under backbone; 

 another record on same date, many cysts in flesh. Mr. Edwards re- 

 ported that 7 out of 100 fish had cysts in the flesh. 



AnguiUa rostrata. 



Collected in 7 of the years from 1904 to 1914, inclusive: On 1 date 

 in April, 1 cyst; 1 date in May, 2 C3^sts, length 4 mm., 1 eel ex- 

 amined; 3 dates in July — (1) few small, pedicelled cysts on viscera, 

 7 eels; (2) characteristic gourd-shaped cysts and plerocerci on 

 mesentery, 5 eels; (3) 20 cysts in walls of stomach and intestine of 

 2 eels; 4 dates in August — (1) few, characteristic cysts on viscera 

 in 3 of 7 eels; (2) numerous cysts in intestinal wall, 1 eel; (3) 



